My career objective is to develop and to apply placental measurement methods to the epidemiology of neurodevelopmental and neuropsychiatric (ND/NP) disorders. As a perinatal pathologist, I seek mentored training in epidemiology (advanced analytic methods as well as perinatal, ND/NP and molecular epidemiology), in order to develop and apply novel methodologies to elucidate how the fetal environment influences risk of ND/NP disorders such as schizophrenia and autism. A key determinant of the fetal environment is the placenta, the organ upon which the embryo/fetus is wholly dependent. Assessment of placental growth and development by gross measurement, and identification of types of placental injury by histologic study, can open a window on fetal life and environment, including the timing and the pathophysiologic mechanism of specific exposures/events that may contribute to pathogenesis of ND/NP disorders. Research into the role of the placenta has been limited in part due to lack of validated measurement instruments for placental pathology. In this career development award I will acquire skills in instrument development and in epidemiologic and birth cohort analyses. As a mentored trainee, I will validate a parsimonious and reliable gross mad histologic instrument for placental measurement across diverse populations and will construct and validate measurement methods that will capture three underlying intrauterine pathophysiology types that may be meaningful to ND/NP risk, namely chronic and acute inflammation and vascular pathology (Aims 1 and 2). I will apply this comprehensive instrument to an existing data set mad conduct a formal analysis of potential pathological mechanisms in the etiology of schizophrenia (an adult-onset disorder with broad epidemiologic evidence of a fetal origin, Aim 3). In Aim 4, I will operationalize my training in birth cohort design by implementing the placental instrument prospectively in a new and large birth cohort, in order to study the effects of placental environment on risk of autism. My career goal is to become an independent perinatal epidemiologist studying the pathophysiology of the critical intrauterine events that contribute to ND/NP compromise, and that may offer opportunities for prevention. My training objectives are directly related to my proposed research, which focuses on the evaluation of the intrauterine environment and how predispositions to ND/NP compromise arise in utero.